Good idea. I keep a few extra cans of gasoline I rotate through every now and then, but I hadn't thought about propane (and maybe some inexpensive heating elements to connect to them).
I had a scare in September when Hurricane Ivan hit Ohio. Usually all that's left when one hits Ohio is a day of rain and 30 mph winds. Instead we got bright sun and 60 mph winds for about 12 hours. Our trees aren't built for that wind so most of the people here lost power. Mine was out for only a day, but some people's power was out for well over a week. I started making more disaster preparations, but I still need to do a lot more. It makes more sense to put money into that than a Chinese high-def television.
We also keep Coleman fuel. A gallon goes a very long time in a camping stove, and since it is almost identical to gasoline, it can power a vehicle or generator. Not having all the additives that pump gas does, it is very stable over time. I have been using it to fuel our lawnmower for over a year now. No problem. Low octane means it would probably ping like crazy in a car, but in an emergency...
Consider a wood stove. Good for cooking, heat, etc. I go through about 2 cords of wood a year. I think good oak is running about $250 a cord, delivered but I have access to plenty of wood.
generator